The use of ball ramp actuators powered by individual motors to load clutch packs in vehicle driveline differentials are well known. The advantage of the ball ramp actuator over other actuators is that it converts rotary motion into axial motion with high force implication. Ball ramp actuator assemblies include a control ring and an activation ring disposed thereon. Both the control and activation rings use opposing variable depth grooves to capture a rolling element for axially expanding and contracting the rings depending on the rotational direction of the activation ring relative to the control ring. The rotary motion of the activation ring is supplied by a motor. To generate an axial force, the activation ring rotates relative to the fixed control ring thereby causing the rolling elements to travel along the grooves of the corresponding rings to push the activation ring in an axial direction. A clutch may be connected to the activation ring such that the axial movement of the activation ring compresses the clutch plates so that they rotate together.
The use of a single motor actuator to rotate a single ball ramp mechanism to control a single clutch results in a complicated system of mechanical and electrical components. If there is more than one clutch, the prior art uses a separate motor actuator and ball ramp assembly for each clutch, further adding to the complication and expense of the system associated with the additional components.